Have a word with britannia they didn't seem to mind folk taking planes away and i think they will also give you a dry rate as well.
If you have a restricted FAA PPL linked to your JAR PPL then yes you can take your girlfriend.
If you are flying about most FBO's have discounted hotels near by for pilots 50% off etc and also some will let you have use of some clapped out old banger of a night as well. Best not ask about insurance though you might not like what you hear.
MJ